LCD (Liquid Crystal Display) possesses advantages of being ultra thin, power saved and radiation free. It has been widely utilized in, such as mobile phones, PDAs (personal digital assistance), digital cameras, laptop screens or notebook screens.
The present thin film transistor liquid crystal display comprises a shell, a LCD panel located in the shell and a backlight module located in the shell. Particularly, the structure of the LCD panel can comprise a TFT Array Substrate (Thin Film Transistor Array Substrate), a CF (Color Filter) and a Liquid Crystal Layer. The working principle is that the light of backlight module is reflected to generate images by applying driving voltages to the two glass substrate for controlling the rotations of the liquid crystal molecules.
The manufacture processes of the thin film transistor liquid crystal display comprises an Array process of the front end, which mainly a TFT substrate and a CF substrate are manufacture; a cell process in the middle, which mainly the TFT substrate and the CF substrate are laminated and liquid crystal is filled therebetween for forming a LCD panel; and a module assembly process of back end, which mainly the LCD panel, the backlight module, a PCB and other components are assembled. In the Array process of the front end and the cell process in the middle, the substrate requires cleaning many times for cleaning the organic matter stick on the surface of the substrate and guaranteeing the substrate spotless. For now, a widely used method of cleaning a substrate is to clean the substrate by ultraviolet rays with photosensitized oxidation of the organic matter. The irradiating wavelength of the ultraviolet ray light is 185 nm and 254 nm which contain high energy. When the light waves reach the surface of the substrate, the organic matter absorbs the energy of the ultraviolet rays with 185 nm wavelength and disaggregates into ions, ionized atoms, excited molecules and neutrons because most of the organic matters have stronger absorbency to the ultraviolet rays with 185 nm wavelength. When the oxygen molecules in the air absorb the ultraviolet rays with 254 nm wavelength, ozone and atomic oxygen are generated. Still, the ozone also have strong absorbency to the ultraviolet rays and then the ozone disaggregates into atomic oxygen and oxygen gas in advance. With the effect of the atomic oxygen, the analyte of the organic matter can be compounded as volatilizable gas, such as carbon dioxide, water vapor and etc. and detached from the surface of the substrate. The cleaning of the organic matter is achieved and a spotless substrate is guaranteed. The specific implement is an ultraviolet ray light is positioned above the substrate. The substrate is moved by a roller conveyer. The ultraviolet rays directly irradiate on the substrate to remove the organic matter. Nevertheless, during this cleaning process, the energy of the ultraviolet rays cannot be flexibly adjusted. Particularly, as the ultraviolet rays are employed for cleaning the TFT substrate, the ultraviolet rays with high energy can easily excite the electrons of the metal layer in the substrate to create massive statics. Ultimately, the static damage can caused to the circuit pattern of the substrate. The quality and the yield of the productions are affected.
Consequently, there is a need for an improved method of cleaning a substrate which is capable of efficiently removing the organic matter stick on the surface of the substrate and preventing the static damage to the circuit pattern of the substrate.